MenAfriNet: A Network Supporting Case-Based Meningitis Surveillance and Vaccine Evaluation in the Meningitis Belt of Africa

Meningococcal meningitis remains a significant public health threat, especially in the African meningitis belt where Neisseria meningitidis serogroup A historically caused large-scale epidemics. With the rollout of a novel meningococcal serogroup A conjugate vaccine (MACV) in the belt, the World Health Organization recommended case-based meningitis surveillance to monitor MACV impact and meningitis epidemiology. In 2014, the MenAfriNet consortium was established to support strategic implementation of case-based meningitis surveillance in 5 key countries: Burkina Faso, Chad, Mali, Niger, and Togo. MenAfriNet aimed to develop a high-quality surveillance network using standardized laboratory and data collection protocols, develop sustainable systems for data management and analysis to monitor MACV impact, and leverage the surveillance platform to perform special studies. We describe the MenAfriNet consortium, its history, strategy, implementation, accomplishments, and challenges.

Case-control vaccine effectiveness studies: Data collection, analysis and reporting results

The case-control methodology is frequently used to evaluate vaccine effectiveness post-licensure. The results of such studies provide important insight into the level of protection afforded by vaccines in a 'real world' context, and are commonly used to guide vaccine policy decisions. However, the potential for bias and confounding are important limitations to this method, and the results of a poorly conducted or incorrectly interpreted case-control study can mislead policies. In 2012, a group of experts met to review recent experience with case-control studies evaluating vaccine effectiveness; we summarize the recommendations of that group regarding best practices for data collection, analysis, and presentation of the results of case-control vaccine effectiveness studies. Vaccination status is the primary exposure of interest, but can be challenging to assess accurately and with minimal bias. Investigators should understand factors associated with vaccination as well as the availability of documented vaccination status in the study context; case-control studies may not be a valid method for evaluating vaccine effectiveness in settings where many children lack a documented immunization history. To avoid bias, it is essential to use the same methods and effort gathering vaccination data from cases and controls. Variables that may confound the association between illness and vaccination are also important to capture as completely as possible, and where relevant, adjust for in the analysis according to the analytic plan. In presenting results from case-control vaccine effectiveness studies, investigators should describe enrollment among eligible cases and controls as well as the proportion with no documented vaccine history. Emphasis should be placed on confidence intervals, rather than point estimates, of vaccine effectiveness. Case-control studies are a useful approach for evaluating vaccine effectiveness; however careful attention must be paid to the collection, analysis and presentation of the data in order to best inform evidence-based vaccine policies.

Case-control vaccine effectiveness studies: Preparation, design, and enrollment of cases and controls

Case-control studies are commonly used to evaluate effectiveness of licensed vaccines after deployment in public health programs. Such studies can provide policy-relevant data on vaccine performance under ‘real world’ conditions, contributing to the evidence base to support and sustain introduction of new vaccines. However, case-control studies do not measure the impact of vaccine introduction on disease at a population level, and are subject to bias and confounding, which may lead to inaccurate results that can misinform policy decisions. In 2012, a group of experts met to review recent experience with case-control studies evaluating the effectiveness of several vaccines; here we summarize the recommendations of that group regarding best practices for planning, design and enrollment of cases and controls. Rigorous planning and preparation should focus on understanding the study context including healthcare-seeking and vaccination practices. Case-control vaccine effectiveness studies are best carried out soon after vaccine introduction because high coverage creates strong potential for confounding. Endpoints specific to the vaccine target are preferable to non-specific clinical syndromes since the proportion of non-specific outcomes preventable through vaccination may vary over time and place, leading to potentially confusing results. Controls should be representative of the source population from which cases arise, and are generally recruited from the community or health facilities where cases are enrolled. Matching of controls to cases for potential confounding factors is commonly used, although should be reserved for a limited number of key variables believed to be linked to both vaccination and disease. Case-control vaccine effectiveness studies can provide information useful to guide policy decisions and vaccine development, however rigorous preparation and design is essential.

Excess Mortality, Hospital Stay, and Cost Due to Candidemia: A Case-Control Study Using Data From Population-Based Candidemia Surveillance

Objective:

To determine the mortality, hospital stay, and total hospital charges and cost of hospitalization attributable to candidemia by comparing patients with candidemia with control-patients who have otherwise similar illnesses. Prior studies lack broad patient and hospital representation or cost-related information that accurately reflects current medical practices.

Design:

Our case-control study included case-patients with candidemia and their cost-related data, ascertained from laboratory-based candidemia surveillance conducted among all residents of Connecticut and Baltimore and Baltimore County, Maryland, during 1998 to 2000. Control-patients were matched on age, hospital type, admission year, discharge diagnoses, and duration of hospitalization prior to candidemia onset.

Results:

We identified 214 and 529 sets of matched case-patients and control-patients from the two locations, respectively. Mortality attributable to candidemia ranged between 19% and 24%. On multivariable analysis, candidemia was associated with mortality (OR, 5.3 for Connecticut and 8.5 for Baltimore and Baltimore County;P< .05), whereas receiving adequate treatment was protective (OR, 0.5 and 0.4 for the two locations, respectively;P< .05). Candidemia itself did not increase the total hospital charges and cost of hospitalization; when treatment status was accounted for, having received adequate treatment for candidemia significantly increased the total hospital charges and cost of hospitalization ($6,000 to $29,000 and $3,000 to $22,000, respectively) and the length of stay (3 to 13 days).

Conclusion:

Our findings underscore the burden of candidemia, particularly regarding the risk of death, length of hospitalization, and cost associated with treatment (Infect Control Hosp Epidemiol2005;26:540-547).

Bacterial meningitis surveillance in the Eastern Mediterranean region, 2005-2010: successes and challenges of a regional network

OBJECTIVE

To describe epidemiology of bacterial meningitis in the World Health Organization Eastern Mediterranean Region countries and assist in introduction of new bacterial vaccines.

STUDY DESIGN

A laboratory-based sentinel surveillance was established in 2004, and up to 10 countries joined the network until 2010. Personnel at participating hospitals and national public health laboratories received training in surveillance and laboratory methods and used standard clinical and laboratory-confirmed case definitions.

RESULTS

Over 22,000 suspected cases of meningitis were reported among children ≤5 years old and >6600 among children >5 years old. In children ≤5 years old, 921 of 13,125 probable cases (7.0%) were culture-confirmed. The most commonly isolated pathogens were S pneumoniae (27% of confirmed cases), N meningitidis (22%), and H influenzae (10%). Among culture-confirmed case-patients with known outcome, case-fatality rate was 7.0% and 12.2% among children ≤5 years old and those >5 years old, respectively. Declining numbers of Haemophilus influenzae type b meningitis cases within 2 years post-Haemophilus influenzae type b conjugate vaccine introduction were observed in Pakistan.

CONCLUSIONS

Bacterial meningitis continues to cause significant morbidity and mortality in the Eastern Mediterranean Region. Surveillance networks for bacterial meningitis ensure that all sites are using standardized methodologies. Surveillance data are useful to monitor impact of various interventions including vaccines, but maintaining data quality requires consistent reporting and regular technical support.

Case control study to identify risk factors for acute hepatitis C virus infection in Egypt

BACKGROUND

Identification of risk factors of acute hepatitis C virus (HCV) infection in Egypt is crucial to develop appropriate prevention strategies.

METHODS

We conducted a case-control study, June 2007-September 2008, to investigate risk factors for acute HCV infection in Egypt among 86 patients and 287 age and gender matched controls identified in two infectious disease hospitals in Cairo and Alexandria. Case-patients were defined as: any patient with symptoms of acute hepatitis; lab tested positive for HCV antibodies and negative for HBsAg, HBc IgM, HAV IgM; and 7-fold increase in the upper limit of transaminase levels. Controls were selected from patients' visitors with negative viral hepatitis markers. Subjects were interviewed about previous exposures within six months, including community-acquired and health-care associated practices.

RESULTS

Case-patients were more likely than controls to have received injection with a reused syringe (OR=23.1, CI 4.7-153), to have been in prison (OR=21.5, CI 2.5-479.6), to have received IV fluids in a hospital (OR=13.8, CI 5.3-37.2), to have been an IV drug user (OR=12.1, CI 4.6-33.1), to have had minimal surgical procedures (OR=9.7, CI 4.2-22.4), to have received IV fluid as an outpatient (OR=8, CI 4-16.2), or to have been admitted to hospital (OR=7.9, CI 4.2-15) within the last 6 months. Multivariate analysis indicated that unsafe health facility practices are the main risk factors associated with transmission of HCV infection in Egypt.

CONCLUSION

In Egypt, focusing acute HCV prevention measures on health-care settings would have a beneficial impact.

Accelerating policy decisions to adopt haemophilus influenzae type B vaccine: a global, multivariable analysis

BACKGROUND

Adoption of new and underutilized vaccines by national immunization programs is an essential step towards reducing child mortality. Policy decisions to adopt new vaccines in high mortality countries often lag behind decisions in high-income countries. Using the case of Haemophilus influenzae type b (Hib) vaccine, this paper endeavors to explain these delays through the analysis of country-level economic, epidemiological, programmatic and policy-related factors, as well as the role of the Global Alliance for Vaccines and Immunisation (GAVI Alliance).

METHODS AND FINDINGS

Data for 147 countries from 1990 to 2007 were analyzed in accelerated failure time models to identify factors that are associated with the time to decision to adopt Hib vaccine. In multivariable models that control for Gross National Income, region, and burden of Hib disease, the receipt of GAVI support speeded the time to decision by a factor of 0.37 (95% CI 0.18-0.76), or 63%. The presence of two or more neighboring country adopters accelerated decisions to adopt by a factor of 0.50 (95% CI 0.33-0.75). For each 1% increase in vaccine price, decisions to adopt are delayed by a factor of 1.02 (95% CI 1.00-1.04). Global recommendations and local studies were not associated with time to decision.

CONCLUSIONS

This study substantiates previous findings related to vaccine price and presents new evidence to suggest that GAVI eligibility is associated with accelerated decisions to adopt Hib vaccine. The influence of neighboring country decisions was also highly significant, suggesting that approaches to support the adoption of new vaccines should consider supply- and demand-side factors.

Establishment of public health security in Saudi Arabia for the 2009 Hajj in response to pandemic influenza A H1N1

Mass gatherings of people challenge public health capacities at host locations and the visitors' places of origin. Hajj--the yearly pilgrimage by Muslims to Saudi Arabia--is one of the largest, most culturally and geographically diverse mass gatherings in the world. With the 2009 pandemic influenza A H1N1 and upcoming Hajj, the Saudi Arabian Ministry of Health (MoH) convened a preparedness consultation in June, 2009. Consultants from global public health agencies met in their official capacities with their Saudi Arabian counterparts. The MoH aimed to pool and share public health knowledge about mass gatherings, and review the country's preparedness plans, focusing on the prevention and control of pandemic influenza. This process resulted in several practical recommendations, many to be put into practice before the start of Hajj and the rest during Hajj. These preparedness plans should ensure the optimum provision of health services for pilgrims to Saudi Arabia, and minimum disease transmission on their return home. Review of the implementation of these recommendations and their effect will not only inform future mass gatherings in Saudi Arabia, but will also strengthen preparedness efforts in other settings.

Brucellosis as a cause of acute febrile illness in Egypt

To develop better estimates of brucellosis incidence, we conducted population-based surveillance for acute febrile illness (AFI) in Fayoum governorate (population 2347249), Egypt during two summer periods (2002 and 2003). All hospitals and a representative sample of community healthcare providers were included. AFI patients without obvious etiology were tested for brucellosis by culture and serology. Incidence estimates were calculated adjusting for sampling methodology and study period. Of 4490 AFI patients enrolled, 321 (7%) met the brucellosis case definition. The estimated annual incidence of brucellosis per 100000 population was 64 and 70 in 2002 and 2003, respectively. The median age of brucellosis patients was 26 years and 70% were male; 53% were initially diagnosed as typhoid fever. Close contact with animals and consumption of unpasteurized milk products were associated with brucellosis. The high incidence of brucellosis in Fayoum highlights its public health importance, and the need to implement prevention strategies in humans and animals.

Population-based surveillance for cryptococcosis in an antiretroviral-naive South African province with a high HIV seroprevalence

OBJECTIVES

To measure the burden of disease and describe the epidemiology of cryptococcosis in Gauteng Province, South Africa.

DESIGN AND METHODS

The study was an active, prospective, laboratory-based, population-based surveillance. An incident case of cryptococcosis was defined as the first isolation by culture of any Cryptococcus species from any clinical specimen, a positive India ink cryptococcal latex agglutination test or a positive histopathology specimen from a Gauteng resident. Cases were identified prospectively at all laboratories in Gauteng. Case report forms were completed using medical record review and patient interview where possible.

RESULTS

Between 1 March 2002 and 29 February 2004, 2753 incident cases were identified. The overall incidence rate was 15.6/100 000. Among HIV-infected persons, the rate was 95/100 000, and among persons living with AIDS 14/1000. Males and children under 15 years accounted for 49 and 0.9% of cases, respectively. The median age was 34 years (range, 1 month-74 years). Almost all cases (97%) presented with meningitis. Antifungal therapy was given to 2460 (89%) cases of which 72% received fluconazole only. In-hospital mortality was 27% (749 cases). Recurrences occurred in 263 (9.5%) incident cases. Factors associated with death included altered mental status, coma or wasting; factors associated with survival included employment in the mining industry, visual changes or headache on presentation.

CONCLUSIONS

This study demonstrates the high disease burden due to cryptococcosis in an antiretroviral-naive South African population and emphasizes the need to improve early recognition, diagnosis and treatment of the condition.

Cryptococcus gattii infection: characteristics and epidemiology of cases identified in a South African province with high HIV seroprevalence, 2002-2004

We describe 46 Cryptococcus gattii-infected persons identified by population-based surveillance conducted in South Africa. Most patients with C. gattii infection presented with meningitis. The mortality rate during hospitalization was 36%. We found no significant differences between persons with and persons without C. gattii infection with regard to clinical presentation, acquired immunodeficiency syndrome diagnosis, concomitant conditions, or prior opportunistic infections. C. gattii isolates had low MICs to the tested antifungal drugs.

Differentiation of tuberculous meningitis from acute bacterial meningitis using simple clinical and laboratory parameters

Tuberculous meningitis (TBM) is still a major cause of serious illness in many parts of the world. The newer diagnostic tests and neuroimaging methods are unlikely to be available in many developing countries. We attempt to identify simple parameters for early diagnosis. A retrospective study was performed to compare the clinical and laboratory features of cultured-confirmed, TBM (134) and other bacterial meningitis (709). Features independently predictive of TBM were studied by multivariate logistic regression to develop a diagnostic rule. Six features were found predictive: length of clinical history >5 days, headache, total cerebrospinal fluid (CSF) white blood cell count of <1000/mm3, clear appearance of CSF, lymphocyte proportion of >30%, and protein content of >100 mg/dL. Application of 3 or more parameters revealed 93% sensitivity and 77% specificity. Applying this diagnostic rule can help in the early diagnosis of TBM, in both children and adults.

Rapid enzyme-linked immunosorbent assay for the diagnosis of human brucellosis in surveillance and clinical settings in Egypt

OBJECTIVE

To optimize and standardize an enzyme-linked immunosorbent assay (ELISA) for rapid diagnosis of human brucellosis in clinical cases identified during a surveillance study for acute febrile illness (AFI).

METHODS

Serum samples from patients presenting with AFI at 13 fever hospitals across Egypt between 1999 and 2003 were kept frozen at NAMRU-3 and used in this study. The assay was evaluated in 5 subject groups: brucellosis cases confirmed by blood culture (group I, n=202) 87% positive by standard tube agglutination test (TA), brucellosis cases exclusively confirmed by TA (group II, n=218), blood cultures from AFI cases positive for bacterial species other than Brucella (group III, n=103), AFI cases with unexplained etiologies (group IV, n=654), and healthy volunteers (group V, n=50). All members of groups III-V were negative for brucellosis by TA.

RESULTS

Sensitivity and specificity of ELISA for total specific antibodies were >=96% versus 87% for TA as compared to microbial culture, the current gold standard method for Brucella identification. Assessment of Brucella antibody classes by ELISA in random subsets of the 5 groups showed significantly high (p>0.001) levels of anti Brucella IgG (>=81%) and IgM (>=90%) in groups I and II only.

CONCLUSION

The obtained sensitivity and specificity results indicate that our ELISA is more suitable for AFI surveillance and clinical settings than blood culture and TA. The developed assay is also cost-effective, easier to use, faster, and the coated plates can be stocked for at least 8 months, providing a potential for field use and automation.

Evaluation of amphotericin B interpretive breakpoints for Candida bloodstream isolates by correlation with therapeutic outcome

One hundred seven Candida bloodstream isolates (51 C. albicans, 24 C. glabrata, 13 C. parapsilosis, 13 C. tropicalis, 2 C. dubliniensis, 2 C. krusei, and 2 C. lusitaniae strains) from patients treated with amphotericin B alone underwent in vitro susceptibility testing against amphotericin B using five different methods. Fifty-four isolates were from patients who failed treatment, defined as death 7 to 14 days after the incident candidemia episode, having persistent fever of >or=5 days' duration after the date of the incident candidemia, or the recurrence of fever after two consecutive afebrile days while on antifungal treatment. MICs were determined by using the Clinical Laboratory Standards Institute (formally National Committee for Clinical Laboratory Standards) broth microdilution procedure with two media and by using Etest. Minimum fungicidal concentrations (MFCs) were also measured in two media. Broth microdilution tests with RPMI 1640 medium generated a restricted range of MICs (0.125 to 1 microg/ml); the corresponding MFC values ranged from 0.5 to 4 microg/ml. Broth microdilution tests with antibiotic medium 3 produced a broader distribution of MIC and MFC results (0.015 to 0.25 microg/ml and 0.06 to 2 microg/ml, respectively). Etest produced the widest distribution of MICs (0.094 to 2 microg/ml). However, none of the test formats studied generated results that significantly correlated with therapeutic success or failure.

Determining risk factors for candidemia among newborn infants from population-based surveillance: Baltimore, Maryland, 1998-2000

BACKGROUND

Our objective was to determine risks factors for late onset candidemia, independent of birth weight, in newborn infants.

METHODS

We performed a matched case-control study. Cases were identified through active, population-based surveillance for candidemia, conducted in Baltimore City and County during 1998-2000, and were defined as the incident isolation of any Candida species from the bloodstream of an infant 3 months old or younger. Four controls, matched by age, hospital, birth weight category, hospital stay and admission date, were selected for each case. Potential risk factors included clinical, demographic and maternal prenatal data.

RESULTS

Of the 35 cases, 19 (54%) infections were with Candida albicans, 9 (26%) were with Candida parapsilosis and 5 (14%) were with Candida glabrata. Cases had a median birth weight of 680 g (range, 430-3200 g); median gestational ages of cases and controls were 25 and 27 weeks, respectively. Compared with controls, cases had significant higher mortality (20% versus 4%; P = 0.004). No maternal factors were associated with increased risk of disease; cases were as likely as controls to be of black race. Multivariable conditional logistic regression analysis revealed that gestational age younger than 26 weeks [adjusted odds ratio, 6.5; 95% confidence interval (95% CI), 1.3-32], vaginal delivery (adjusted odds ratio, 4.3; 95% CI 1.3-14.2) and abdominal surgery (adjusted odds ratio, 10.9; 95% CI 1.9-62) were independently associated with increased risk of candidemia.

CONCLUSIONS

Independent of birth weight, infants born at <26 weeks or those who have had abdominal surgery are at a significantly increased risk of candidemia. This study helps define a subgroup of preterm infants at high risk of developing bloodstream infections with Candida species.

An Epidemic of Coccidioidomycosis in Arizona Associated with Climatic Changes, 1998–2001

BACKGROUND

Reports of coccidioidomycosis cases in Arizona have increased substantially. We investigated factors associated with the increase.

METHODS

We analyzed the National Electronic Telecommunications System for Surveillance (NETSS) data from 1998 to 2001 and used Geographic Information Systems (GIS) to map high-incidence areas in Maricopa County. Poisson regression analysis was performed to assess the effect of climatic and environmental factors on the number of monthly cases; a model was developed and tested to predict outbreaks.

RESULTS

The overall incidence in 2001 was 43 cases/100,000 population, a significant (P<.01, test for trend) increase from 1998 (33 cases/100,000 population); the highest age-specific rate was in persons > or =65 years old (79 cases/100,000 population in 2001). Analysis of NETSS data by season indicated high-incidence periods during the winter (November-February). GIS analysis showed that the highest-incidence areas were in the periphery of Phoenix. Multivariable Poisson regression modeling revealed that a combination of certain climatic and environmental factors were highly correlated with seasonal outbreaks (R2=0.75).

CONCLUSIONS

Coccidioidomycosis in Arizona has increased. Its incidence is driven by seasonal outbreaks associated with environmental and climatic changes. Our study may allow public-health officials to predict seasonal outbreaks in Arizona and to alert the public and physicians early, so that appropriate preventive measures can be implemented.

Candidemia in pediatric outpatients receiving home total parenteral nutrition

This is a cohort study of pediatric outpatients receiving total parenteral nutrition (TPN) and follow-up care in a Tennessee hospital between January and June 1999. The study was conducted following an increase in the incidence of candidemia. Of 13 children receiving home TPN, five had candidemia; three were due to Candida parapsilosis. Case patients were more likely to have an underlying hematologic disease (P = 0.02) as well as previous history of fungemia (P = 0.02). Two case patients had successive candidemia episodes 3 months apart; karyotypes and RAPD profiles of each patient's successive C. parapsilosis isolates were similar. Candida spp. were frequently detected in hand cultures from cohort members (four of 10) and family member caregivers (nine of 11); C parapsilosis was isolated from five caregivers. Our findings underscore the challenges of maintaining stringent infection control practices in the home health care setting and suggest the need for more intensive follow-up and coordination of home TPN therapy among pediatric patients.

Epidemiologic and molecular characterization of an outbreak of Candida parapsilosis bloodstream infections in a community hospital

Candida parapsilosis is an important cause of bloodstream infections in the health care setting. We investigated a large C. parapsilosis outbreak occurring in a community hospital and conducted a case-control study to determine the risk factors for infection. We identified 22 cases of bloodstream infection with C. parapsilosis: 15 confirmed and 7 possible. The factors associated with an increased risk of infection included hospitalization in the intensive care unit (adjusted odds ratio, 16.4; 95% confidence interval, 1.8 to 148.1) and receipt of total parenteral nutrition (adjusted odds ratio, 9.2; 95% confidence interval, 0.9 to 98.1). Samples for surveillance cultures were obtained from health care worker hands, central venous catheter insertion sites, and medical devices. Twenty-six percent of the health care workers surveyed demonstrated hand colonization with C. parapsilosis, and one hand isolate was highly related to all case-patient isolates by tests with the DNA probe Cp3-13. Outbreak strain isolates also demonstrated reduced susceptibilities to fluconazole and voriconazole. This largest known reported outbreak of C. parapsilosis bloodstream infections in adults resulted from an interplay of host, environment, and pathogen factors. Recommendations for control measures focused on improving hand hygiene compliance.

A large histoplasmosis outbreak among high school students in Indiana, 2001

BACKGROUND

A histoplasmosis outbreak occurred in an Indiana high school in November-December 2001.

METHODS

To describe the risk factors for this outbreak, we conducted a cohort study of all available students and staff (N = 682) and an environmental investigation.

RESULTS

Of the 523 (77%) persons who displayed serologic evidence of recent Histoplasma capsulatum infection, 355 (68%) developed symptoms consistent with acute pulmonary histoplasmosis. Rototilling of soil in a school courtyard known to be a bird roosting site had been performed during school hours on November 12, 2001, 14 days before both the peak of the onset of illness and a rise in student absenteeism. Being a student (odds ratio, 3.3; 95% confidence interval, 2.2-5.0) and being a student in a classroom near the courtyard during the rototilling (odds ratio, 3.1; 95% confidence interval, 1.8-5.2) were independently associated with infection and symptomatic illness. H. capsulatum was isolated from environmental samples, including soil from the courtyard and dust collected from a filter of a heating, ventilating and air-conditioning system.

CONCLUSIONS

Soil-disrupting activities within a school courtyard caused the largest outbreak to date of histoplasmosis among adolescents. Improved efforts are needed to educate the community in endemic areas about histoplasmosis to prevent the occurrence of such outbreaks in the future. In addition, increased awareness among health care providers of this disease would facilitate appropriate diagnosis and treatment.

Candida parapsilosis characterization in an outbreak setting

Candida parapsilosis is an important non-albicans species which infects hospitalized patients. No studies have correlated outbreak infections of C. parapsilosis with multiple virulence factors. We used DNA fingerprinting to determine genetic variability among isolates from a C. parapsilosis outbreak and from our clinical database. We compared phenotypic markers of pathogenesis, including adherence, biofilm formation, and protein secretion (secretory aspartic protease [SAP] and phospholipase). Adherence was measured as colony counts on silicone elastomer disks immersed in agar. Biofilms formed on disks were quantified by dry weight. SAP expression was measured by hydrolysis of bovine albumin; a colorimetric assay was used to quantitate phospholipase. DNA fingerprinting indicated that the outbreak isolates were clonal and genetically distinct from our database. Biofilm expression by the outbreak clone was greater than that of sporadic isolates (p < 0.0005). Adherence and protein secretion did not correlate with strain pathogenicity. These results suggest that biofilm production plays a role in C. parapsilosis outbreaks.

Coccidioidomycosis among workers at an archeological site, northeastern Utah

In 2001, an outbreak of acute respiratory disease occurred among persons working at a Native American archeological site at Dinosaur National Monument in northeastern Utah. Epidemiologic and environmental investigations were undertaken to determine the cause of the outbreak. A clinical case was defined by the presence of at least two of the following symptoms: self-reported fever, shortness of breath, or cough. Ten workers met the clinical case definition; 9 had serologic confirmation of coccidioidomycosis, and 8 were hospitalized. All 10 were present during sifting of dirt through screens on June 19; symptoms began 9–12 days later (median 10). Coccidioidomycosis also developed in a worker at the site in September 2001. A serosurvey among 40 other Dinosaur National Monument workers did not find serologic evidence of recent infection. This outbreak documents a new endemic focus of coccidioidomycosis, extending northward its known geographic distribution in Utah by approximately 200 miles.

Histoplasmosis associated with exploring a bat-inhabited cave in Costa Rica, 1998-1999

Between October 1998 and April 1999, 51 persons belonging to two separate groups developed acute pulmonary histoplasmosis after visiting a cave in Costa Rica. The first group consisted of 61 children and 14 adults from San Jose, Costa Rica; 44 (72%) were diagnosed with acute histoplasmosis. The second group comprised 14 tourists from the United States and Canada; 9 (64%) were diagnosed with histoplasmosis. After a median incubation time of 14 days, the most common symptoms were headache, fever, cough, and myalgias. Risk factors for developing histoplasmosis included crawling (odds ratio [OR] = 17.5, 95% confidence interval [CI] = 2.3-802) and visiting one specific room (OR = 3.4, 95% CI = 1.0-12.3) in the cave. Washing hands (OR = 0.1, 95% CI = 0.01-0.6) after exiting the cave was associated with a decreased risk of developing histoplasmosis. Histoplasma capsulatum was isolated from bat guano collected from inside the cave. Persons who explore caves, whether for recreation or science, should be aware of the risk bat-inhabited caves pose for developing histoplasmosis, especially if they are immunocompromised in any way.

Incidence of bloodstream infections due to Candida species and in vitro susceptibilities of isolates collected from 1998 to 2000 in a population-based active surveillance program

To determine the incidence of Candida bloodstream infections (BSI) and antifungal drug resistance, population-based active laboratory surveillance was conducted from October 1998 through September 2000 in two areas of the United States (Baltimore, Md., and the state of Connecticut; combined population, 4.7 million). A total of 1,143 cases were detected, for an average adjusted annual incidence of 10 per 100,000 population or 1.5 per 10,000 hospital days. In 28% of patients, Candida BSI developed prior to or on the day of admission; only 36% of patients were in an intensive care unit at the time of diagnosis. No fewer than 78% of patients had a central catheter in place at the time of diagnosis, and 50% had undergone surgery within the previous 3 months. Candida albicans comprised 45% of the isolates, followed by C. glabrata (24%), C. parapsilosis (13%), and C. tropicalis (12%). Only 1.2% of C. albicans isolates were resistant to fluconazole (MIC, > or = 64 microg/ml), compared to 7% of C. glabrata isolates and 6% of C. tropicalis isolates. Only 0.9% of C. albicans isolates were resistant to itraconazole (MIC, > or = 1 micro g/ml), compared to 19.5% of C. glabrata isolates and 6% of C. tropicalis isolates. Only 4.3% of C. albicans isolates were resistant to flucytosine (MIC, > or = 32 microg/ml), compared to < 1% of C. parapsilosis and C. tropicalis isolates and no C. glabrata isolates. As determined by E-test, the MICs of amphotericin B were > or = 0.38 microg/ml for 10% of Candida isolates, > or =1 microg/ml for 1.7% of isolates, and > or = 2 microg/ml for 0.4% of isolates. Our findings highlight changes in the epidemiology of Candida BSI in the 1990s and provide a basis upon which to conduct further studies of selected high-risk subpopulations.

Blastomycosis in Missouri: epidemiology and risk factors for endemic disease

Between 1992 and 1999, 93 cases of blastomycosis, including 25 laboratory confirmed cases, were identified in Missouri (annual incidence, 0.2/100,000 population). Mississippi County in southeastern Missouri had the highest incidence (12/100,000) with a much higher rate among blacks than whites in this county (43.21/100,000). The mortality rate, 44% was also higher among blacks. To determine risk factors for endemic blastomycosis, a case-control study was conducted among southeastern Missouri residents. Independent risk factors for blastomycosis were black race and a prior history of pneumonia. No environmental exposures or socioeconomic factors were significantly associated with increased risk. The increased risk among blacks may possibly be related to genetic factors, but further studies are needed to clarify this. However, heightened awareness of the disease and a better understanding of the risk factors are important and may lead to earlier diagnosis and start of treatment, possibly improving outcome.

A large outbreak of histoplasmosis among American travelers associated with a hotel in Acapulco, Mexico, spring 2001

During spring 2001, college students from Pennsylvania reported an acute febrile respiratory illness after returning from spring break vacation in Acapulco, Mexico. Acute pulmonary histoplasmosis was presumptively diagnosed and the cluster of illness was reported to the Centers of Disease Control and Prevention. A large investigation then ensued, which included finding student-travelers for interviews and requesting sera for histoplasmosis testing. We defined a clinical case by fever and at least one of the following: cough, shortness of breath, chest pain, or headache, in an Acapulco traveler during March-May 2001. A laboratory-confirmed case had positive serology. An initial study determined that the likely site of histoplasmosis exposure was Hotel H; we therefore performed a large cohort study among travelers who stayed at Hotel H. Of 757 contacted, 262 (36%) met the clinical case definition. Of 273 serum specimens tested, 148 (54%) were positive. Frequent use of Hotel H's stairwells, where construction was ongoing, was associated with increased risk of illness (relative risk = 10.5, 95% confidence interval = 3.7-30.5; P < 0.001). This is the first histoplasmosis outbreak associated with a hotel undergoing construction. Hotels in endemic areas should consider construction precaution measures to prevent histoplasmosis among their guests.

Outbreak of dengue fever in Palau, Western Pacific: risk factors for infection

Between January and June 1995, an outbreak of dengue fever occurred in Palau, an island nation of 32,000 inhabitants in the Western Pacific. To determine the magnitude of this outbreak and to determine modifiable risk factors to guide control strategies, we established active surveillance at the national hospital and private clinics, reviewed available clinical records, and conducted serologic and entomologic surveys. Between January 1 and July 1, 1995, 817 case-patients with acute febrile illness with body or joint aches and one of the following: headache, rash, nausea, vomiting, or hemorrhagic manifestations presented to health facilities in Palau. The epidemic peaked in the second week of April 1995. Of 338 case-patients tested, 254 (75%) had positive serologic results by an IgM capture enzyme-linked immunosorbent assay. Dengue 4 virus was isolated from 78 (51%) of 154 serum samples tested. Blood samples collected during a cross-sectional survey were tested for IgM antibody and yielded an attack ratio of 27% (95% confidence interval = 23-31%). Potential vectors included the introduced species Aedes aegypti and Ae. albopictus, and the native species Ae. hensilli. Significant risk factors (P < or = 0.05) for infection included age < 20 years, the presence of food or water pans for animals on the property, taro farming, the presence of Ae. aegypti on the property, and presence of Ae. scutellaris group mosquitoes (Ae. Hensilli, Ae. albopictus, and a native species). This was the first outbreak of dengue 4 virus in the Western Pacific, and the first documented epidemic of dengue in Palau since 1988.

Outbreak of invasive aspergillosis among renal transplant recipients

Invasive aspergillosis (IA) is rare among renal transplant recipients (RTRs). We investigated a cluster of IA among RTRs at a California hospital from January to February 2001, when construction was ongoing. We conducted a cohort study among RTRs who were hospitalized between January 1 and February 5, 2001, to determine risk factors for IA. IA was defined using established guidelines. Four IA cases occurred among 40 RTRs hospitalized during the study period. Factors associated with an increased risk of IA included prolonged hemodialysis, lengthy corticosteroid treatment posttransplant, and use of sirolimus alone or with mycophenolate (P<0.05). After the study period, three additional RTRs developed IA; two Aspergillus isolates recovered from these patients had indistinguishable profiles by DNA fingerprinting, suggesting common-source exposure. This study suggests that immunosuppressed RTRs can be at an increased risk for IA. Measures to prevent IA in these patients should be taken during hospital construction.

The changing epidemiology of cryptococcosis: an update from population-based active surveillance in 2 large metropolitan areas, 1992-2000

To examine trends in the incidence and epidemiology of cryptococcosis, active, population-based surveillance was conducted during 1992-2000 in 2 areas of the United States (the Atlanta, Georgia, and Houston, Texas, metropolitan areas; combined population, 7.4 million). A total of 1491 incident cases were detected, of which 1322 (89%) occurred in HIV-infected persons. The annual incidence of cryptococcosis per 1000 persons with AIDS decreased significantly during the study period, from 66 in 1992 to 7 in 2000 in the Atlanta area, and from 24 in 1993 to 2 in 1994 in the Houston area. Poisson regression analysis revealed that African American persons with AIDS were more likely than white persons with AIDS to develop disease. Less than one-third of all HIV-infected persons with cryptococcosis were receiving antiretroviral therapy before diagnosis. Our findings suggest that HIV-infected persons who continue to develop cryptococcosis in the era of highly active antiretroviral therapy (HAART) in the United States are those with limited access to health care. More efforts are needed to expand the availability of HAART and routine HIV care services to these persons.

Stability of allelic frequencies and distributions of Candida albicans microsatellite loci from U.S. population-based surveillance isolates

Allelic distributions and frequencies of five Candida albicans microsatellite loci have been determined for strains isolated from the bloodstream and obtained through active population-based surveillance in two U.S. metropolitan areas between 1998 and 2000. These data were compared to data for isolates obtained from two other U.S. regions in 1992 to 1993. In a majority of pairwise combinations between sites, no evidence was seen for shifts in microsatellite allelic frequencies. One to three alleles were highly predominant and correlated with major genotypes. These data both support the concepts of allelic stability and genetic equilibria and suggest that, in the United States, strains of C. albicans isolated from the bloodstream may form a defined, genetically homogeneous population across geographical distance and time.

Human immunodeficiency virus type 1 subtype and other factors associated with extrapulmonary Cryptococcosis among patients in Thailand with AIDS

Delineating factors associated with extrapulmonary cryptococcosis (EPC), a major disease burden among Thailand's AIDS patients, can clarify its pathogenesis and guide preventive interventions. From November 1993 through June 1996, enhanced surveillance of 2261 human immunodeficiency virus (HIV)-seropositive patients in a hospital near Bangkok showed EPC among 561 of 1553 AIDS patients (36.1%). Univariate analysis results were confirmed by multivariate analyses of data on 1259 patients. Logistic regression models identified factors significantly associated with EPC to be male sex (adjusted odds ratio [aOR], 2.0; 95% confidence interval [CI], 1.3-2.9), age <33 years (aOR, 1.5; 95% CI, 1.2-1.9), severe immunosuppression (aOR, 1.8; 95% CI, 1.3-2.6), not injecting drugs (aOR, 3.0; 95% CI, 1.7-5.5), and infection with HIV-1 circulating from CRF01_AE (formerly subtype E) versus subtype B (aOR, 2.3; 95% CI, 1.2-4.5). The association with CRF01_AE may result from undetermined markers of exposure or viral subtype effects on host immune responses. Better understanding of the epidemiology of EPC may reduce EPC incidence through targeted primary prevention and treatment.

Population-based surveillance and a case-control study of risk factors for endemic lymphocutaneous sporotrichosis in Peru

Population-based surveillance and a case-control study were conducted in Abancay, Peru, to estimate the burden of disease and to determine risk factors for sporadic lymphocutaneous sporotrichosis (LS). Laboratory records from local hospitals were reviewed for the years of 1997 and 1998, and prospective surveillance was conducted for the period of September 1998 through September 1999. A case-control study was conducted with 2 matched control subjects per case patient. The mean annual incidence was 98 cases per 100,000 persons. Children had an incidence 3 times higher than that for adults and were more likely to have LS lesions on the face and neck. Identified risk factors included owning a cat, playing in crop fields, having a dirt floor in the house, working mainly outdoors, and having a ceiling made of raw wood or conditions associated with a lower socioeconomic status. Decreased environmental exposure, such wearing protective clothing during construction activities for adults or limiting contact with cats and soil for children, and improvements in living spaces may decrease the incidence of LS.

Recent trends in the epidemiology of invasive mycoses

PURPOSE OF REVIEW

Invasive mycoses are emerging as an important public health problem. This development has occurred in large measure due to the increasing numbers of persons at risk. In addition, advances in therapeutic technologies and in particular the development of novel immunosuppressive therapies have prolonged the period of risk for many individuals.

RECENT FINDINGS

Although rates of candida bloodstream infections have been increasing over the past several decades, recent evidence suggests this trend may be reversing. The emergence of non-albicans Candida species, and in particular C. glabrata, has been documented. Invasive aspergillosis and other mold infections have become a significant and increasing problem in hematopoietic stem cell transplant recipients and certain high-risk groups of solid organ transplant recipients. These infections are associated with high mortality rates. Despite marked reductions in the rates of AIDS-associated fungal infections in the USA and other developed countries, the burden of these mycoses in developing countries is large and increasing.

SUMMARY

While gains have been made in the treatment and prevention of invasive mycoses, changes in the epidemiology of these infections and in healthcare practices have resulted in the emergence of new at-risk populations. A better understanding of specific risk factors will be needed if prevention strategies, such as chemoprophylaxis and environmental control measures, are to become more widely applicable and cost-effective.

Fungal infections among returning travelers

Endemic mycoses, such as histoplasmosis, coccidioidomycosis, and penicilliosis, have emerged as important health threats among travelers to regions of the world where these infections are endemic. Travelers have developed fungal infections as a result of a wide range of recreational and work activities, many of which have involved well-recognized risk factors for these diseases. In some instances, infections have been acquired during short trips, whereas, in other instances, infection has been acquired during a longer period of residence in an area where the infection is endemic. Travelers need to be made aware of the risks of acquiring mycotic diseases when visiting such regions. Health care providers need to consider these infections in their differential diagnosis among returning travelers with respiratory illness and should be familiar with the treatment and prevention of these diseases.

Inhalational anthrax outbreak among postal workers, Washington, D.C., 2001

In October 2001, four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility that processed envelopes containing Bacillus anthracis spores. We reviewed the envelopes' paths and obtained exposure histories and nasal swab cultures from postal workers. Environmental sampling was performed. A sample of employees was assessed for antibody concentrations to B. anthracis protective antigen. Case-patients worked on nonoverlapping shifts throughout the facility, suggesting multiple aerosolization events. Environmental sampling showed diffuse contamination of the facility. Potential workplace exposures were similar for the case-patients and the sample of workers. All nasal swab cultures and serum antibody tests were negative. Available tools could not identify subgroups of employees at higher risk for exposure or disease. Prophylaxis was necessary for all employees. To protect postal workers against bioterrorism, measures to reduce the risk of occupational exposure are necessary.

Opening a bacillus anthracis-containing envelope, Capitol Hill, Washington, D.C.: the public health response

On October 15, 2001, a U.S. Senate staff member opened an envelope containing Bacillus anthracis spores. Chemoprophylaxis was promptly initiated and nasal swabs obtained for all persons in the immediate area. An epidemiologic investigation was conducted to define exposure areas and identify persons who should receive prolonged chemoprophylaxis, based on their exposure risk. Persons immediately exposed to B. anthracis spores were interviewed; records were reviewed to identify additional persons in this area. Persons with positive nasal swabs had repeat swabs and serial serologic evaluation to measure antibodies to B. anthracis protective antigen (anti-PA). A total of 625 persons were identified as requiring prolonged chemoprophylaxis; 28 had positive nasal swabs. Repeat nasal swabs were negative at 7 days; none had developed anti-PA antibodies by 42 days after exposure. Early nasal swab testing is a useful epidemiologic tool to assess risk of exposure to aerosolized B. anthracis. Early, wide chemoprophylaxis may have averted an outbreak of anthrax in this population.

Secular trend of hospital-acquired candidemia among intensive care unit patients in the United States during 1989-1999

We describe the annual incidence of primary bloodstream infection (BSI) associated with Candida albicans and common non-albicans species of Candida among patients in intensive care units that participated in the National Nosocomial Infections Surveillance system from 1 January 1989 through 31 December 1999. During the study period, there was a significant decrease in the incidence of C. albicans BSI (P<.001) and a significant increase in the incidence of Candida glabrata BSI (P=.05).

Comparison of visual and spectrophotometric methods of broth microdilution MIC end point determination and evaluation of a sterol quantitation method for in vitro susceptibility testing of fluconazole and itraconazole against trailing and nontrailing Candida isolates

Visual determination of MIC end points for azole antifungal agents can be complicated by the trailing growth phenomenon. To determine the incidence of trailing growth, we performed testing of in vitro susceptibility to fluconazole and itraconazole using the National Committee for Clinical Laboratory Standards broth microdilution M27-A reference procedure and 944 bloodstream isolates of seven Candida spp., obtained through active population-based surveillance between 1998 and 2000. Of 429 C. albicans isolates, 78 (18.2%) showed trailing growth at 48 h in tests with fluconazole, and 70 (16.3%) showed trailing in tests with itraconazole. Of 118 C. tropicalis isolates, 70 (59.3%) showed trailing growth in tests with fluconazole, and 35 (29.7%) showed trailing in tests with itraconazole. Trailing growth was not observed with any of the other five Candida spp. tested (C. dubliniensis, C. glabrata, C. krusei, C. lusitaniae, and C. parapsilosis). To confirm whether or not isolates that showed trailing growth in fluconazole and/or itraconazole were resistant in vitro to these agents, all isolates that showed trailing growth were retested by the sterol quantitation method, which measures cellular ergosterol content rather than growth inhibition after exposure to azoles. By this method, none of the trailing isolates was resistant in vitro to fluconazole or itraconazole. For both agents, a 24-h visual end point or a spectrophotometric end point of 50% reduction in growth relative to the growth control after 24 or 48 h of incubation correlated most closely with the result of sterol quantitation. Our results indicate that MIC results determined by either of these end point rules may be more predictive of in vivo outcome for isolates that give unclear visual end points at 48 h due to trailing growth.

Automatic electronic laboratory-based reporting of notifiable infectious diseases at a large health system

Electronic laboratory-based reporting, developed by the UPMC Health System, Pittsburgh, Pennsylvania, was evaluated to determine if it could be integrated into the conventional paper-based reporting system. We reviewed reports of 10 infectious diseases from 8 UPMC hospitals that reported to the Allegheny County Health Department in southwestern Pennsylvania during January 1-November 26, 2000. Electronic reports were received a median of 4 days earlier than conventional reports. The completeness of reporting was 74% (95% confidence interval [CI] 66% to 81%) for the electronic laboratory-based reporting and 65% (95% CI 57% to 73%) for the conventional paper-based reporting system (p>0.05). Most reports (88%) missed by electronic laboratory-based reporting were caused by using free text. Automatic reporting was more rapid and as complete as conventional reporting. Using standardized coding and minimizing free text usage will increase the completeness of electronic laboratory-based reporting.

Surveillance for unexplained deaths and critical illnesses due to possibly infectious causes, United States, 1995-1998

Population-based surveillance for unexplained death and critical illness possibly due to infectious causes (UNEX) was conducted in four U.S. Emerging Infections Program sites (population 7.7 million) from May 1, 1995, to December 31, 1998, to define the incidence, epidemiologic features, and etiology of this syndrome. A case was defined as death or critical illness in a hospitalized, previously healthy person, 1 to 49 years of age, with infection hallmarks but no cause identified after routine testing. A total of 137 cases were identified (incidence rate 0.5 per 100,000 per year). Patients' median age was 20 years, 72 (53%) were female, 112 (82%) were white, and 41 (30%) died. The most common clinical presentations were neurologic (29%), respiratory (27%), and cardiac (21%). Infectious causes were identified for 34 cases (28% of the 122 cases with clinical specimens); 23 (68%) were diagnosed by reference serologic tests, and 11 (32%) by polymerase chain reaction-based methods. The UNEX network model would improve U.S. diagnostic capacities and preparedness for emerging infections.

Epidemiology and Prevention of Invasive Aspergillosis

Aspergillus species are the most common causes of invasive mold infections in immunocompromised persons. This review examines the available information regarding the rising incidence of invasive aspergillosis in different high-risk groups, including persons with acute leukemia, hematopoietic stem cell transplant recipients, and liver and lung transplant recipients. The risk factors for infection in these groups are discussed. Because Aspergillus species are widespread in the environment, it is difficult to link specific sources and exposures to the development of human infections. However, molecular strain typing and other studies indicate that a significant number of Aspergillus infections are now being acquired outside the health care setting, either before patients are admitted to hospital, or after they have been discharged. The role of environmental control measures and antifungal drug prophylaxis in the prevention of hospital- and community-acquired aspergillosis is discussed.

Counterpoint: invasive aspergillosis and the environment--rethinking our approach to prevention

Preventive measures are important in the control of invasive aspergillosis (IA) because diagnosis is difficult and the outcome of treatment is poor. If effective strategies are to be devised, it will be essential to have a clearer understanding of the sources and routes of transmission of Aspergillus species. Nosocomial outbreaks of IA highlight the fact that Aspergillus spores are common in the hospital environment. However, in general, such outbreaks are uncommon. Most cases of IA are sporadic in nature, and many of them are now being acquired outside of the hospital setting. Housing patients in high-energy particulate air-filtered hospital rooms helps prevent IA, but it is feasible and cost-effective only for the highest-risk groups and for limited periods. Control measures, which are designed to protect patients from exposure to spores outside the hospital, are even more difficult. Nevertheless, now that high-risk patients are spending more time outside of the hospital, the cost benefits of antifungal prophylaxis and other preventive measures require careful evaluation.

Trends in antifungal drug susceptibility of Cryptococcus neoformans isolates in the United States: 1992 to 1994 and 1996 to 1998

The antifungal drug susceptibilities of two collections of Cryptococcus neoformans isolates obtained through active laboratory-based surveillance from 1992 to 1994 (368 isolates) and 1996 to 1998 (364 isolates) were determined. The MICs of fluconazole, itraconazole, and flucytosine were determined by the National Committee for Clinical Laboratory Standards broth microdilution method; amphotericin B MICs were determined by the E-test. Our results showed that the MIC ranges, the MICs at which 50% of isolates are inhibited (MIC(50)s), and the MIC(90)s of these four antifungal agents did not change from 1992 to 1998. In addition, very small numbers of isolates showed elevated MICs suggestive of in vitro resistance. The MICs of amphotericin B were elevated (>or=2 microg/ml) for 2 isolates, and the MICs of flucytosine were elevated (>or=32 microg/ml) for 14 isolates. Among the azoles, the fluconazole MIC was elevated (>or=64 microg/ml) for 8 isolates and the itraconazole MIC (>or=1 microg/ml) was elevated for 45 isolates. Analysis of 172 serial isolates from 71 patients showed little change in the fluconazole MIC over time. For isolates from 58 patients (82% of serial cases) there was either no change or a twofold change in the fluconazole MIC. In contrast, for isolates from seven patients (12% of serial cases) the increase in the MIC was at least fourfold. For isolates from another patient there was a 32-fold decrease in the fluconazole MIC over a 1-month period. We conclude that in vitro resistance to antifungal agents remains uncommon in C. neoformans and has not significantly changed with time during the past decade.

Trends in mortality due to invasive mycotic diseases in the United States, 1980-1997

To determine national trends in mortality due to invasive mycoses, we analyzed National Center for Health Statistics multiple-cause-of-death record tapes for the years 1980 through 1997, with use of their specific codes in the International Classification of Diseases, Ninth Revision (ICD-9 codes 112.4-118 and 136.3). In the United States, of deaths in which an infectious disease was the underlying cause, those due to mycoses increased from the tenth most common in 1980 to the seventh most common in 1997. From 1980 through 1997, the annual number of deaths in which an invasive mycosis was listed on the death certificate (multiple-cause [MC] mortality) increased from 1557 to 6534. In addition, rates of MC mortality for the different mycoses varied markedly according to human immunodeficiency virus (HIV) status but were consistently higher among males, blacks, and persons > or =65 years of age. These data highlight the public health importance of mycotic diseases and emphasize the need for continuing surveillance.

Adenovirus type 3 viremia in an adult with toxic shock-like syndrome

Surveillance by the Unexplained Deaths and Critical Illnesses Project (UNEX) uncovered a novel presentation of adenovirus type 3 infection that satisfied the criteria for toxic shock-like syndrome in a 28-year-old immunocompetent man. Adenovirus may be a cause of toxic shock syndrome; surveillance systems such as UNEX may uncover additional causes of this and other clinically defined infectious syndromes.

Epidemiology: surveillance of fungal infections

Surveillance for fungal diseases is essential to improve our understanding of their epidemiology and to enable research and prevention efforts to be prioritized. In order to conduct better surveillance for fungal diseases, it is important to develop more accurate and timely diagnostic tests, to follow rigorous epidemiological methods and to have adequate support from public health agencies and the pharmaceutical industry. Investigations of nosocomial and community outbreaks of fungal infection have also resulted in a better understanding of the sources and routes of transmission of these diseases, and of the risk factors for infection. This has led to more effective prevention and control strategies. In addition, outbreak investigations have offered excellent opportunities to develop new molecular sub-typing methods, and to evaluate and validate older ones. For example, results obtained from a global epidemiological study of the genomic structure of Cryptococcus neoformans have led to a better understanding of the epidemiology of cryptococcosis. Similarly, a study of variations in the genotype of Trichophyton rubrum has found that patients may become infected with multiple strains, which has important implications for study design when looking at the epidemiology of dermatophyte infections.

The epidemiology of histoplasmosis: a review

Histoplasmosis is the most common endemic mycosis in the United States and has recently emerged as an important opportunistic infection among human immunodeficiency virus (HIV)-infected persons living in areas where it is endemic. In this article, we describe the epidemiologic and ecologic features of histoplasmosis, highlighting the implications for prevention. Surveillance and education of the public and health care providers are needed to determine the disease burden of histoplasmosis. Development of better diagnostic tests for detection of disease in humans and of the organism in the environment will help in designing better prevention strategies.

Gastrointestinal basidiobolomycosis in Arizona: clinical and epidemiological characteristics and review of the literature

Gastrointestinal basidiobolomycosis (GIB) is an unusual fungal infection that is rarely reported in the medical literature. From April 1994 through May 1999, 7 cases of GIB occurred in Arizona, 4 from December 1998 through May 1999. We reviewed the clinical characteristics of the patients and conducted a case-control study to generate hypotheses about potential risk factors. All patients had histopathologic signs characteristic of basidiobolomycosis. Five patients were male (median age, 52 years; range, 37--59 years) and had a history of diabetes mellitus (in 3 patients), peptic ulcer disease (in 2), or pica (in 1). All patients underwent partial or complete surgical resection of the infected portions of their gastrointestinal tracts, and all received itraconazole postoperatively for a median of 10 months (range, 3--19 months). Potential risk factors included prior ranitidine use and longer residence in Arizona. GIB is a newly emerging infection that causes substantial morbidity and diagnostic confusion. Further studies are needed to better define its risk factors and treatment.

Multicenter case-control study of risk factors for histoplasmosis in human immunodeficiency virus-infected persons

We conducted a multicenter case-control study to identify risk factors for histoplasmosis among persons with acquired immunodeficiency syndrome (AIDS) and to evaluate predictors of a poor outcome (defined as death or admission to the intensive care unit). Patients with histoplasmosis were each matched by age, sex, and CD4 lymphocyte count to 3 controls. From 1996 through 1999, 92 case patients and 252 controls were enrolled. Of the case patients, 81 (89%) were men, 50 (55%) were black, 78 (85%) had a CD4 lymphocyte count of <100 cells/microL, 80 (87%) were hospitalized, and 11 (12%) died. Multivariable analysis found that receipt of antiretroviral therapy and of triazole drugs were independently associated with a decreased risk of histoplasmosis. Chronic medical conditions and a history of infections with herpes simplex virus were associated with poor outcome. Triazoles should be considered for chemoprophylaxis for persons with AIDS, especially those who take part in high-risk activities that involve frequent exposure to soil, who have CD4 lymphocyte counts of <100 cells/microL, and who live in areas where histoplasmosis is endemic.